Workflow systems known in the art allow automatic execution of a sequence of processing activities expressed in a workflow description. A typical pattern that can be found in workflows is to extract business data from a variety of different data sources and to combine that data for further processing in subsequent activities in the workflow.
In such systems, the various data processing activities within a workflow are directed to each particular data source individually containing the data in question, such as a particular relational database system of a specific system vendor. Thus, users of the workflow system design workflows in which portions of the required business data are obtained by writing a plurality of data requests which are each particularly directed to the appropriate data source, for instance using Standard Query Language (SQL) statements.
Further, the various data portions thus acquired need to be combined to become the desired set of data to be processed in the further execution of the workflow, requiring additional technical effort for programming proprietary code for combining the data. This is an additional burden to the workflow system user, since the code is typically difficult to develop and thus a potential source of errors in data processing. Moreover, combining data from various sources oftentimes is inefficient and resource-consuming.
Furthermore, federated data management systems are known in the art. A federated database system is a type of meta-database management system which transparently integrates multiple autonomous database systems into a single federated database. Thus, these systems integrate heterogeneous data from various databases and provide a uniform front-end user interface to let data requested from the system appear as being from a single data source.
Using federated database systems with existing workflow systems has proven to require a significant amount of additional technical complexity that has to be handled by the user of a workflow system. In order to address the federated database system from the workflow system, the user would need to understand the federated system, particularly how to integrate additional data sources into the system and how to map concepts from his workflow system to concepts of the federated system. In case of changes of the integration logic of the workflow, the user might need to refer to the federated system and find out which changes need to be applied before being able to return to the workflow system and change the workflow accordingly.
Thus, it would be desirable to have a workflow management system and a method of automatic workflow processing in such a system, and a computer system, data processing program, computer program product, and computer data signal therefore, each of which enables automated execution of a workflow while acquiring data from a number of different data sources in a manner transparent to the user of the workflow system while avoiding the disadvantages of the systems of the state of the art.